Prof. Katharina von Salis made an important point by questioning common practice to restrict drug testing to a non-representative sub-population (young, healthy men) of future consumers. A similar flaw applies to most animal experiments. For example, in order to study the function of a specific receptor in the brain, the gene for that receptor may be knocked out and the effect on behaviour assessed in a sample of mice - usually young, healthy males. However, it is not only the standard sex and age of the animals that is worrying when such a general question is approached. It is also that the animals usually share an identical genetic background (genetic standardization) and have been reared under identical environmental conditions (environmental standardization). Although the concept of standardization is fundamentally at odds with biological thinking, it has become a hallmark of good laboratory practice in animal experimentation. It serves to reduce variation within and between study populations in order to increase reproducibility of results. But: do we really want to spend huge sums of research money for findings that reproduce well, but only within a specific brand of genetically homogeneous animals that have lived through a standardized sequence of environmental events? It came as a shock for the scientific community when three scientists published a paper in Science two years ago, reporting that one and the same experiment produced fundamentally different results in three different labs, although they had standardized everything that can possibly be standardized across labs (Crabbe et al. 1999). The question may therefore be raised: how many experiments that are conducted at ETH have the potential to produce truely informative results? Well, to speak with Prof. von Salis: who wants to know? Crabbe et al. 1999. Genetics of Mouse Behavior: Interactions with Laboratory Environment. Science 284, 1670-1672.